The role of the perpheral amide groups of B12-coenzyme in the interaction between coenzyme and apo-protein will be investigated. Studies of the mechanism of action of fluorinated enzyme inactivators will be carried out. The mechanism of action cystathionine-beta-synthase will be investigated. BIBLIOGRAPHIC REFERENCES: Maycock, A. L., Abeles, R. H., Salach, J. I., and Singer, T. P. The Structure of the Covalent Adduct Formed by the Interaction of 3-Dimethylamino-1-propyne and the Flavine of Mitochondrial Amine Oxidase. Biochemistry 15, 114 (1976). Sato, K., Orr, J. C., Babior, B., and Abeles, R. H. The Mechanism of Action of Etanolamine Ammonia-Lyase. An Adenosylcobalamin-Dependent Enzyme. J. Biol. Chem. 251, 3734-3737 (1976).